CJ-2A Wiring Diagram Sanity Check

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After 4 plus years, I'm finally beginning to wire the '47. A couple years ago, I purchased a wiring harness from KW for a 6 volt system with turn signals and horn on the inner fender. Otherwise, the KW wire harness starting and charging circuits are the standard 6v 2A systems - which is not what I'm doing. 
I've converted everything over to 12 volts, 10 SI 3-wire alt, solenoid, key switch and push button starter on the left dash. The key switch has 3 terminal on the back, AMM, ACC and Coil. I have searched this site and the interwebs for wiring like I'm doing with the parts I have and nothing quite matches up to the starting and charging circuits I want to set up. 
The fancy dry-erase board is my attempt at making sense of how I need to wire. I'll be using inline fuses rather than a fuse panel under the dash. I have made many revisions to get to this point. In my research, on the new wire harness I need for the right side of the engine, I found Rhode Island Wire (riwire.com) as a supplier for cloth covered wire similar to original wiring.
Asking if you see any issues with this wiring diagram and always appreciate your comments / suggestions. Thanks, John

Edited by JohnB - 25 Feb. 2020 at 10:46pm

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JohnB Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 01 June 2014 Location: Saint Louis, MO Status: Offline Points: 393	Post Options Post Reply Quote JohnB Report Post Thanks(0) Quote Reply Topic: CJ-2A Wiring Diagram Sanity Check Posted: 25 Feb. 2020 at 3:03am
	After 4 plus years, I'm finally beginning to wire the '47. A couple years ago, I purchased a wiring harness from KW for a 6 volt system with turn signals and horn on the inner fender. Otherwise, the KW wire harness starting and charging circuits are the standard 6v 2A systems - which is not what I'm doing. I've converted everything over to 12 volts, 10 SI 3-wire alt, solenoid, key switch and push button starter on the left dash. The key switch has 3 terminal on the back, AMM, ACC and Coil. I have searched this site and the interwebs for wiring like I'm doing with the parts I have and nothing quite matches up to the starting and charging circuits I want to set up. The fancy dry-erase board is my attempt at making sense of how I need to wire. I'll be using inline fuses rather than a fuse panel under the dash. I have made many revisions to get to this point. In my research, on the new wire harness I need for the right side of the engine, I found Rhode Island Wire (riwire.com) as a supplier for cloth covered wire similar to original wiring. Asking if you see any issues with this wiring diagram and always appreciate your comments / suggestions. Thanks, John Edited by JohnB - 25 Feb. 2020 at 10:46pm

squidtone Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 05 Mar. 2016 Location: CT Status: Offline Points: 42	Post Options Post Reply Quote squidtone Report Post Thanks(0) Quote Reply Posted: 26 Feb. 2020 at 1:54am
	I recently did my own 12V harness for my Jeep, so I've got some observations: I don't think you need the diode in the Pin 1 circuit of the Delco 10SI. I think the "idiot light" is enough. I would run your Pin 2 of the Delco alternator to your "-" side of your ammeter....this is where you are distributing most of your electrical power, and that is a good place for the alternator Pin 2 (the "sense" wire). I'm a bit confused on the ignition switch pinout....so I would assume the "AMM" is always +12volt input for the ignition switch, and "coil" is the output for the "ON" position for the switch, and "ACC" is stuff like your heater motor or radio when you want to run it without the ignition on. If that's the case, I'd prefer to run the fuel gauge on the "Coil" terminal on the ignition switch. I wouldn't think it necessary to power that gauge when the ignition switch is in the "ACC" position. Your dash light is wired so that if you leave it on, you will drain the battery even with the key off. Maybe move that from the (-) ammeter to the ACC of the ignition switch. Is your fuel gauge 12 volt? I forget if voltage matters in the balanced coil design of those things. Lastly, is your coil internal or external resistor? If external resistor, you can buy a 1.6 ohm ballast resistor and wire it in series with the feed from the ignition switch. These low compression motors don't need alot of power to jump the spark plug gap! Have fun!
	Dave

JohnB Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 01 June 2014 Location: Saint Louis, MO Status: Offline Points: 393	Post Options Post Reply Quote JohnB Report Post Thanks(0) Quote Reply Posted: 26 Feb. 2020 at 3:36am
	Dave, thanks for taking a look at this and your suggestions. I looked at a lot of 2A diagrams. My goal was to stay as original to the 47 wiring as I could, but modify where necessary. I was unclear about the alternator diode too. How do you know if you need or not? I will have the idiot light and when I get the engine running, I can see if the system will charge without the diode. I'll move the alternator T2 wire as you suggested. Your assumption on the key switch is correct, AMM is power into the switch. Turn key to left for ACC and turn key all the way to the right for On or Coil. You make a good point on the dash light being left on. This is where I went off a standard 2A wiring set up and that is how it was done. I may move as you suggest - at least no one will find the switch under the left side of the dash! Gas gauge is 12v and has a ground terminal - so I'm running a dedicated ground wire from the fuel sender back to the gauge. The coil has an internal resistor so I'm good there. Just like everyone else that totally or partially rewires their jeep, the goal is to have no excitement when the battery is hooked up! Getting closer to a running jeep! Please send any other comments. Thanks again, John Before and after painting. Edited by JohnB - 26 Feb. 2020 at 3:46am

squidtone Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 05 Mar. 2016 Location: CT Status: Offline Points: 42	Post Options Post Reply Quote squidtone Report Post Thanks(0) Quote Reply Posted: 26 Feb. 2020 at 4:01am
	The alternator will definitely work with just the "idiot light" bulb, otherwise known as a charge indicator light. I've done it this way on two different vehicles, including my Jeep. I put in halogen headlights and the alternator keeps 'em super bright! One thing to note about the "idiot light": sometimes when I start my Jeep it comes to life and just idles low with no fanfare....it's just on the edge of not being high enough RPM to "light up" the alternator fields, so the "idiot light" stays lit. A quick blip of the throttle brings up the RPM momentarily, and the light goes out, and stays out even when RPM goes back down. It's not a problem, it's a feature of super smooth flathead engines. HAHA Anyway, some folks don't want an idiot light, so they use a diode instead. Use one or the other. Have fun wiring up your Jeep. I enjoyed creating my own harness and it was fun seeing all the stuff come to life while building it. Nice Jeep by the way!
	Dave

a4cj2a77 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 03 Sep. 2012 Location: Seal Beach Ca. Status: Offline Points: 566	Post Options Post Reply Quote a4cj2a77 Report Post Thanks(0) Quote Reply Posted: 26 Feb. 2020 at 4:06am
	Looks good, wishing my 2a came that color. My favorite color combo, green and yellow wheels. Phil

Steelyard Blues Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 09 Oct. 2017 Location: Reno, NV Status: Offline Points: 1496	Post Options Post Reply Quote Steelyard Blues Report Post Thanks(0) Quote Reply Posted: 26 Feb. 2020 at 4:51am
	In my opinion, the "idiot light" is unnecessary. It is used when you don't have an ammeter. We are 2A owners and therefore are not idiots. All you need to do is look at the ammeter and see if it is on the positive side. As to the diode, I had to use one on my original keyed coil. A diode is a one way valve. The sensing wire would otherwise back feed your coil and you would not be able to turn off the engine. I recently switched over to a modern switch but retained the floor switch. I'm not sure if you have the sensing wire on a different terminal other than the ignition (coil) that you would still get power to the sensing wire but not bleed over to the ignition. I picked up a nice plug/diode alternator wiring set up off eBay. I consider the three wires coming off the alternator to be Battery, Load and Sense. Load determines what charge the alternator puts out. Sense is what turns on the alternator. I recently rewired my charging system using 8 gauge wire and ran a 14 gauge load wire to the positive (battery) side of the ammeter rather than the negative (load) side. I don't think there is much difference. What year is your 2A? My dash light is controlled by a little switch above my left foot. Later models had it incorporated into the headlight switch. I like the little switch because that is the way she came. I plan to add the WWII circuit breaker assembly to the dash support bracket as the military jeeps had. You can have some protection for your accessories and your ignition/fuel gauge circuit which is otherwise not protected. Everything else should be protected by the headlight switch breaker. https://www.kaiserwillys.com/new-circuit-breaker-bracket-w-breakers-fits-41-45-mb-gpw As to the fuel gauge, it is essentially a resistance meter. The sender is the negative side of the meter. I think it is more important to have the TANK grounded. If not well grounded, the sender will have extra ground resistance which in turn will be read by the meter. You can still ground the gauge. Original gauges did not have this and got their ground through the mount. Micah Edited by Steelyard Blues - 26 Feb. 2020 at 5:27am
	1947 CJ2A 106327, Engine J109205, Tub 97077. Luzon Red https://www.thecj2apage.com/forums/steelyard-blues_topic41024_post397981.html?KW=micah+movie#397981 1965 Johnson Furnace Company M416 #6-1577

JohnB Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 01 June 2014 Location: Saint Louis, MO Status: Offline Points: 393	Post Options Post Reply Quote JohnB Report Post Thanks(0) Quote Reply Posted: 26 Feb. 2020 at 5:40am
	Thanks for the feedback and comments. It's a '47 #89982 - the dash light switch is tucked under the dash on the far driver's side. The photo brings the green out - the color is Picket Gray, that has a greenish tint to it. Wheels will be painted Harvard Red in the spring. I really appreciate the help with the wiring from those that have experience on these 2As! Edited by JohnB - 26 Feb. 2020 at 5:48am

Steelyard Blues Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 09 Oct. 2017 Location: Reno, NV Status: Offline Points: 1496	Post Options Post Reply Quote Steelyard Blues Report Post Thanks(0) Quote Reply Posted: 27 Feb. 2020 at 2:18am
	Nice looking! I hope to get there some day. In the mean time, I don't worry about beating her up a bit. I made my own harness using the deteriorated original as a guide. It was a good way to learn how it is put together. Not a whole lot to these Jeeps. Getting the alternator correct can be a bit of work. Make sure you use a decent gauge wire for the battery side. I used a LED bulb for the dash light. You can leave it on for a week and it probably wont do anything to the battery. This is the diode harness I mentioned: https://www.ebay.com/itm/Anti-Feed-Back-Diode-Harness-10SI-12SI-15SI-27SI-Delco-Alternator-Regulator-Lead/152043261434?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 A little dielectric grease works well to keep the terminals from corroding. Micah
	1947 CJ2A 106327, Engine J109205, Tub 97077. Luzon Red https://www.thecj2apage.com/forums/steelyard-blues_topic41024_post397981.html?KW=micah+movie#397981 1965 Johnson Furnace Company M416 #6-1577

JohnB Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 01 June 2014 Location: Saint Louis, MO Status: Offline Points: 393	Post Options Post Reply Quote JohnB Report Post Thanks(0) Quote Reply Posted: 27 Feb. 2020 at 2:46am
	Micah, Thanks for the lead on the diode harness. I did purchase a large tube of die electric grease to use on all the connections. I was lucky to find this jeep (I think) in an unmolested condition. It hadn't run in 12 or 15 years before I got it - now it's 20 years since it ran on the road. I had the engine rebuilt and I've already run the engine in the frame on temporary starter wiring and lots of metal work on the tub and 1/2 cab. Looking forward to actually driving in the spring and taking the grandsons for their first ride. A full restoration is a big, long and expensive project. I fully understand why people says fix what needs to be fixed and drive it. I didn't have that option - I thought I knew what a restoration meant when I started - now I know. I do know that everyone on this forum keep us motivated and help get these 2As back on the road.